The visible or luminous matter in the universe is approximately 76 percent hydrogen and 24 percent helium, by mass. Astrophysicists have shown that in order to account for certain motions of astronomical bodies there must be a very large amount of mass in the universe that has not been observed. This is called "dark matter" or "missing mass" and is estimated to represent 90 percent of the mass of the universe. The universe also appears to be electrically neutral with the same number of electrons as protons.
A valuable reference work providing background art relative to the invention is Nuclear and Particle Physics by W. S. C. Williams, Clarendon Press Oxford, 1991, particularly chapters 14, 13, and 11. In section 14.2, Big Bang Nucleosynthesis, it describes various nuclear reactions that began to take place 225 seconds after the Big Bang. The output of many of those reactions are alpha particles with kinetic energies of the order of 10 MeV. One of those nuclear reactions is: EQU Li.sup.7 +p.fwdarw..alpha.+.alpha.+17.35 MeV
About 106 years after the Big Bang, normal atoms began to form in the universe. Chapter 11 covers the subject of kinetic energy loss of charged particles by ionization of a metal's atoms by charged particles moving through the metals. The term "range" is defined as the distance moved by a charged particle through a metal before coming to rest. To determine the range for particular particles of a given energy, the number surviving various thicknesses of metal foils is measured. For alpha particles of energy up to tens of MeV, the survival rate is very nearly 100 percent until a certain thickness of a given material, after which the number of alpha particles drops to zero rapidly.
It is known that the ionization energy of the first electron removed from a stationary helium atom is 24.6 electron volts. When that electron is removed, it no longer partially shields the second electron from the two proton positive charge of the alpha particle nucleus and the second electron moves closer to the nucleus, resulting in an ionization energy for the lone electron of 54.4 electron volts.
The latest information about dark matter can be found in Stephen Hawking's Universe by David Filkin, Basic Books, a Division of Harper Collins Publishers, Inc., 1997, in chapters 8 and 9. After much research, astrophysicists have convincing evidence of dark matter. They have ruled out several possible sources of dark matter and are now focusing on weakly interacting, massive particles. Through the massive gravitational effects of dark matter, the existence of dark matter has been proven but its particle structure remains unknown as of the end of 1997.
In 1932, Cockcroft and Walton conducted experiments which demonstrated experimentally that beams of protons, with kinetic energy of only 120,000 eV, are capable of breaking up the nucleus of the lithium atom and thereby creating two high energy alpha particles, according to the nuclear reaction: EQU Li.sup.7 +p.fwdarw..alpha.+.alpha.+17.35 MeV
See Atomic Physics by Max Born, Dover Publications, Inc. 1969, page 71 and 73. Later experimenters disintegrated the lithium with protons down to less than 30,000 ev.
This same nuclear reaction is believed to have occurred in the universe during the Big Bang nucleosynthesis and since that time. The two alpha particles are known to be emitted in opposite directions to satisfy the conservation of momentum law.
A closely related reaction involving lithium-6 and deuterium also can be achieved on earth and produces even higher energy alpha particles: EQU Li.sup.6 +D.fwdarw..alpha.+.alpha.+22.4 MeV
It is an object of this invention to devise a method and apparatus to create and detect a structure of elementary particles that is weakly interacting, is difficult to detect by absorption spectrum techniques, and could be created in the universe by nuclear reactions known to have taken place there. Another object of this invention is to create a structure of particles that is a possible candidate for the dark matter of the universe and subject them to detection methods that can be used as a basis for understanding or detecting the dark matter of the universe. Another object of the invention is to create and detect highly energetic, partially neutralized beams of alpha particles for possible use for cancer treatments and possibly for medical imaging.